Nike Flex RN 2018Boys' Running Shoe (3.5y-7y)CONNECT TO YOUR RUN.Top to bottom, Nike Flex RN 2018 Boys' Running Shoe (3.5y-7y) is built to flex. Its circular-knit upper stretches in key areas, while the dynamic heel design and molded tri-star outsole pattern work together for an adaptive ride that connects you to your run.